DIY vs. Professional Assistance: The Risks of Crafting a Cohabitation Agreement on Your Own

Why Some Couples Choose the DIY Approach

Perceived Cost Savings and Convenience

One of the main reasons couples opt for a DIY cohabitation agreement is the belief that they can save money by avoiding legal fees. In an effort to cut costs, they may turn to free or inexpensive templates found online and modify them to fit their situation. Compared to the hourly rates of a family lawyer, this option can seem much more affordable—especially when couples assume their situation is uncomplicated.

Additionally, DIY agreements offer the convenience of drafting on your own schedule, without needing to book appointments, attend consultations, or wait on legal reviews. For many, especially younger couples or those just starting out, it feels like a quick, no-fuss solution.

Access to Online Templates and Generic Legal Forms

The internet is full of downloadable legal templates and standard agreements that promise to help couples create binding contracts with minimal effort. These generic documents often include standard clauses and prompts, giving the impression that anyone can fill them out without legal training.

However, these templates typically fail to account for Ontario-specific family law requirements or unique relationship dynamics. They may use vague language, miss mandatory disclosures, or include clauses that are unenforceable in court. Without expert guidance, couples may unknowingly sign an agreement that provides no real protection.

Desire to Avoid Involving Lawyers in Personal Matters

Another factor influencing the DIY approach is the desire for privacy. Some couples feel that bringing in lawyers might escalate tension or signal mistrust. They may view legal involvement as intrusive or overly formal for what they see as a mutual understanding.

Key Legal Risks of a DIY Cohabitation Agreement

Lack of Enforceability Due to Improper Drafting

The most serious risk of a DIY cohabitation agreement is that it may not be enforceable in court. Without legal expertise, couples often include ambiguous language or rely on terminology that fails to meet legal standards. Even small errors in wording can result in confusion or misinterpretation, making it difficult for a judge to uphold the terms.

For example, failing to clearly define what qualifies as “separate” versus “joint” property could lead to conflicting interpretations during separation. If the agreement lacks legal precision, the court may disregard it altogether, leaving partners vulnerable to default family law outcomes.

Missing Required Elements: Full Financial Disclosure, Clarity, or Proper Witnessing

Ontario’s Family Law Act requires certain procedural steps to ensure that a cohabitation agreement is valid:

• Full and frank financial disclosure from both parties
• Clear and unambiguous language
• Proper signatures and independent witnessing

If any of these elements are missing, the agreement can be challenged. For instance, if one party later claims they were unaware of the other’s full financial situation at the time of signing, the court may find that the agreement was signed under false pretences or duress.

Similarly, failing to have the agreement signed in the presence of a witness—or using an ineligible witness—can invalidate the document. These technical oversights are common in DIY agreements and can render them legally useless when they’re needed most.

Risk of Agreement Being Overturned by the Court During a Dispute

Even if a DIY agreement appears valid on paper, it is vulnerable to being set aside by a judge if challenged. This is especially likely if:

• One party claims they didn’t understand what they were signing
• The agreement is heavily one-sided or unconscionable
• There is evidence of coercion or unequal bargaining power
• The agreement hasn’t been updated despite major life changes (e.g., having children)

Courts in Ontario will not hesitate to override a cohabitation agreement if they believe it’s unfair, unclear, or did not meet legal requirements at the time it was signed. In some cases, a flawed agreement can create more conflict than if no agreement had existed at all.

Importance of Independent Legal Advice

Courts Give More Weight to Agreements Reviewed by Lawyers

Ontario courts are far more likely to uphold a cohabitation agreement when both parties have received legal advice from separate, qualified family law lawyers. This demonstrates that the individuals:

• Fully understood the nature and consequences of the agreement
• Entered into the contract voluntarily and without pressure
• Had the opportunity to ask questions and raise concerns

When a court sees that both parties received ILA, the agreement is presumed to be more balanced, informed, and fair, making it less vulnerable to being overturned during a legal dispute.

Prevents Claims of Coercion, Misunderstanding, or Unfairness

One of the most common reasons cohabitation agreements are set aside in Ontario is a claim of duress, coercion, or misunderstanding. If one party later alleges they didn’t fully comprehend the agreement or were pressured into signing it, the absence of independent legal advice can significantly undermine the document’s validity.

By obtaining ILA, each partner confirms in writing that they understand the terms and accept them willingly. This legal safeguard helps prevent future claims of:

• “I didn’t know what I was signing”
• “I didn’t realise I was giving up spousal support rights”
• “I was pressured into signing by my partner”

Having a lawyer explain the terms in plain language ensures transparency and informed consent, which are key principles under Ontario family law.

Helps Both Parties Understand Long-Term Legal Implications

Many people enter into cohabitation agreements without truly considering how the terms will affect them years later. A lawyer can help each party:

• Assess the long-term impact of waiving spousal support or property rights
• Identify potential unfair clauses or gaps in the agreement
• Plan for future events, such as having children, buying a home, or retirement

Legal advice isn’t just about protecting you now—it’s about making sure the agreement remains relevant and sustainable as your life evolves. Without this guidance, couples may sign agreements that are outdated or harmful when circumstances change.

Common Clauses Often Misinterpreted or Omitted in DIY Versions

Property Ownership and Division Upon Separation

One of the most important sections of a cohabitation agreement deals with property ownership—especially in cases where one partner brings a home or major asset into the relationship. DIY agreements often fail to:

• Clearly define which assets are individually owned and which are jointly owned
• Establish whether growth in value (e.g., appreciation on a home) will be shared
• Set rules for buyouts, sale of shared property, or division of contents upon separation

When this clause is missing or ambiguous, it may lead to lengthy disputes about who owns what—particularly if both parties have contributed financially or otherwise to the same asset.

Spousal Support Expectations or Waivers

In Ontario, common-law spouses may be entitled to spousal support after a relationship ends, depending on the length of the relationship and the degree of economic dependence. A properly drafted cohabitation agreement can include:

• A spousal support waiver to prevent future claims
• Clear terms about eligibility, duration, or amount of support
• Conditions that trigger or terminate support (e.g., cohabiting with a new partner)

DIY agreements frequently omit spousal support provisions altogether or include poorly worded waivers that fail legal tests. Without legal advice, one or both parties may wrongly assume that support won’t apply—only to be surprised during a separation.

Handling Debts, Pensions, and Jointly Acquired Assets

A thorough cohabitation agreement should also address how shared debts and jointly acquired property will be handled if the relationship ends. This includes:

• Credit card or personal loan obligations
• Joint bank accounts and shared investments
• Pension contributions or employment benefits accumulated during the relationship

DIY templates often skip these critical areas, leaving couples exposed to shared liability for each other’s debts or conflicts over assets acquired together. Even seemingly minor oversights—like failing to specify who keeps the car or who is responsible for paying off a shared line of credit—can lead to costly legal battles.

Real-World Scenarios: When DIY Agreements Failed

Ontario Case Law Where Agreements Were Set Aside

Ontario courts have set aside multiple cohabitation agreements for failing to meet legal standards. A common thread in these rulings is the absence of full financial disclosure or independent legal advice. For example:

• In M. v. J.H., the court refused to uphold a cohabitation agreement where one partner claimed they did not fully understand the implications of waiving spousal support, and there was no evidence they received legal advice.
• In another Ontario case, a court invalidated an agreement because one party failed to disclose significant real estate holdings, creating an imbalance of power and information.

These examples underline the court’s priority: ensuring that agreements are fair, informed, and voluntary—criteria that DIY documents often fail to meet.

Examples of Costly Legal Battles Due to Vague or Invalid Terms

DIY cohabitation agreements frequently include ambiguous clauses, such as:

• “Each partner keeps their own stuff.”
• “Spousal support is not expected.”
• “The house belongs to whoever paid the most for it.”

Without precise definitions or context, such language can lead to prolonged litigation. In several Ontario disputes, partners who once trusted each other were forced to spend tens of thousands of dollars in court fighting over property ownership, debt responsibility, and entitlement to support—all because their agreement was poorly drafted or unenforceable.

What began as an attempt to avoid legal costs ultimately resulted in higher financial losses, delayed resolutions, and emotional strain.

Emotional and Financial Toll of Unclear Agreements

When a DIY cohabitation agreement breaks down in the face of separation, it’s not just a legal issue—it’s a deeply emotional experience. Disputes over what was meant or intended can lead to:

• Strained co-parenting relationships
• Disruption of shared housing or finances
• Increased anxiety and mistrust during the legal process
• Financial depletion due to court fees and legal representation

Even couples with the best of intentions can find themselves in conflict when faced with the uncertainty of a vague or outdated agreement. The fallout can have a long-term impact on both parties’ well-being and financial stability.